Logan Airport – November 3, 1973

On the morning of November 3, 1973, Pan American World Airways Flight 160 departed J.F. K. International Airport in New York bound for Scotland.

The aircraft was a Boeing 707-321C (N458PA). It was a scheduled cargo flight, with a crew of three aboard; the captain, John J. Zammett, 53, the first officer, Gene W. Ritter, 34, and the flight engineer, Davis Melvin, 37. There were not passengers.

The aircraft was carrying 16,000 pounds of chemicals including cylinders of nitric acid, and other types of acids. The manifest also included 5,000 pounds of mail, 16,000 pounds of electrical components, and another 16,000 pounds of “miscellaneous items”.

At 9:04 a.m. Flight 160 advised Pan American Operations that they had a smoke condition on board and were diverting to Boston.

At 9:10 a.m. Flight 160 advised the smoke was getting thicker. A minute later they requested emergency equipment to be on hand when they landed.

As the plane approached Boston it was given “preferential air traffic control treatment” even though no emergency had been declared by the flight crew.

At 9:31 a.m. Captain Zammett was asked if he was declaring an emergency, to which he replied, “Negative on the emergency, and may we have Runway 33 left?” The request was granted.

By 9:38 a.m. the aircraft was about four miles from the airport, but its transponder had evidently stopped working. One minute later Flight 160 crashed 262 feet from the edge of Runway 33L.

Witnesses later reported that just before the crash they saw the left cockpit window open with smoke streaming out, and the plane was doing yaw and roll maneuvers before the left wing and nose slammed into the ground at a nearly vertical angle. The plane was destroyed and all three men aboard were killed.

The cause of the crash was determined to be excessive smoke in the cockpit which hampered the crew’s ability to control the aircraft. As to the cause of the smoke, the NTSB investigation report, in Section 16 of the Technical Report Standard Title Page, stated in part, “Although the source of the smoke could not be established conclusively, the Safety Board believes that the spontaneous chemical reaction between leaking nitric acid , improperly packaged and stowed, and the improper sawdust packing surrounding the acid’s package initiated the accident sequence.”